A process control system normally comprises a number of process control objects involved in the control of the process.
In process control systems there are furthermore maintenance engineers that are most of the time working on the process floor close to these process control objects, which is typically far away from control rooms with work stations and other computers from which the system is monitored. The maintenance engineers make sure the process runs as smooth as possible by both preventive and direct maintenance.
These maintenance engineers strongly depend on the operators located in the control room to get access to process data from the process control objects they need to perform their work on.
There do exist remote desktop solutions for mobile terminals in order to allow the maintenance engineers to work independently and not having to rely on help from operators located in the control room. This allows the maintenance engineers to view process data, view status of process graphics, make adjustments to process control objects and get information from the process control system. This means that maintenance engineers no longer have the same need for a constant backup from an operator.
There is a problem in that a remote desktop solution is not flexible in that normally a user has to start from the same position in the graphical representation of the system before reaching a process control object in which he or she is interested. Furthermore, the displays of mobile terminals are small and there may be a need for a selection which process control objects are to be presented.
U.S. Pat. No. 7,043,310 describes the use of Personal Digital Assistants (PDAs) or mobile radio telephones in automation systems. In this document, the nearest automation component to a process control object is displayed on a display of a PDA or a mobile radio telephone.
U.S. Pat. No. 5,598,572 in turn describes an information terminal system including a process control computer and a portable terminal device for inputting information to the process control computer and gaining information from the process control. The system includes component information storing means for storing information for distinguishing each one of plural components composing a plant and component identifying means for identifying a component from plural components composing a plant and existing in the direction indicated by and at the location of the portable terminal device, by using information for distinguishing each one of the plural components stored in the component information storing means.
U.S. Pat. No. 7,194,446 describes the rendering of an HMI (Human Machine Interface) based on the proximity of a user to a zone. If the user is within the zone then the HMI may be set to only display the machinery of the zone. There is thus a binary type of display. If the user is in a zone all devices in the zone are displayed.
A similar approach is used in EP 2077473. If a user is in a certain control area, then the user is granted or denied access to the area based on user privileges, where the access may be the access only to the area. The user may more particularly be allowed to only view or configure devices that are in the control area.
Despite the teachings of the above mentioned documents, there is still a need for improvement within the field.
The present invention addresses one or more of the above-mentioned problems.